minimal switch from pyflann to cyflann

tests all fail now....
fix cyflann usage; forgot to sqrt the result
whole loop body no-GIL. still working on the header.
Merge branch 'master' into cyflann

Conflicts:
	sdm/np_divs.py
switch knn_search to use cyflann

It's only used in the non-working jensen_renyi, but still.
push the nogil out a little farther
Merge branch 'master' into reparallel
fix slight bug in test_divs
reparallel; fails on linear, everything else good...
fix the bug that was making linear come out wrong
change setup.py cython process, etc
ignore cython_debug folders
parallelize! it segfaults if flann has openmp, though :(
Merge branch 'master' into reparallel